I think I am fine with center sharpness... however the corners are a bit worrisome... especially at 24 mm... this is supposedly the best 24mm canon has at corners... should I be concerned? I know I shot the "wall" but it is straight and plane

Yes, I'd go for a replacement, except that I'm just sitting back and seeing how everyone is doing with theirs. So far, I've read about a lot of sample variation, which is a bit disgusting. I'd consider the Tamron, except it seems to have even more issues with QC.Once you have found a good one, never let it go.

yeah i'm hanging onto my 24-70 mk1 for now its a good one, see how this plays out first

I think I am fine with center sharpness... however the corners are a bit worrisome... especially at 24 mm... this is supposedly the best 24mm canon has at corners... should I be concerned? I know I shot the "wall" but it is straight and plane

Were there such issues with the first of the 70-200 mk2's also? And with 16-35 mk2 ? And if so, did they get better or did people just accept them?

The reason why I'm asking is if this is a 24-70 mk2 issue, it's pretty useless... this is a very expensive lens and not that fast and should be almost no sample variation... I'd be pretty upset I think...

I had troubles getting consistent AFMA results once and I had to change the process. I found that consistently shooting in the same spot was my challenge. Here's the process (bear with me) that I used.

-Mount the camera to your tripod and level it out-Tether the camera to your PC. -Mount the lens align target on a tripod and level it out. I get it as close as possible to MFD. Ideally, you have an old tripod that has a crank to raise and lower it.-Open the EOS utility and go to live shooting.-Click test shot.-Zoom to x1-If the scroll bar on the side of the test shot lines up in the middle, great. If not, raise and lower the target until you achieve this. (see pic below) -From there, you can adjust the AFMA. I was VERY delicate when pushing the buttons so as not to move the camera.-Keep it tethered throughout the adjustment process so there is no variation.

This helped me to get consistent results. If you're doing this already, my apologies. Just offering up a solution that helped me.

The reason why I'm asking is if this is a 24-70 mk2 issue, it's pretty useless... this is a very expensive lens and not that fast and should be almost no sample variation... I'd be pretty upset I think...

Agreed, and even though Canon had copy variability with the original, you'd think they'd have learned from that...

I was very interested in this lens when it was announced, but instead of pre-ordering it, I put those funds toward my 600 II. Now, I'm even more happy that I did that. I'm now actually considering the 50/1.2L instead of the 24-70 II.

-Mount the lens align target on a tripod and level it out. I get it as close as possible to MFD.

That's a bad idea, unless you're always shooting at the MFD. The adjustment at the MFD is often quite different from the adjustment at other focus distances, and once you get a ways out from the lens, the adjustment values tend to get much more stable. That is why LensAlign recommends 25x the focal length, and Canon recommends 50x the focal length (i.e., about 8 ft and 16 ft, respectively, for a 100mm lens).

The keys to getting consistent results are a stable tripod and LOTS of light. Personally, I have 450 W of light pointed at the target from a distance of a little over 1 foot.